Fluid pressure device



Dec. 7, 1943. w. H. REA 2,336,294

FLUID PRESSURE DEVICE Filed Aug. 14, 1942 2`Sheets-Sheet l 22 l E 2l L 2O l 29 6 T n l [06 j 351 27 25 'vvswro/z WILL/nm H. Een,

' @Y HTT'ORNEY.

Dec. 7, 1943..r W, H, REA 2,336,294

FLUID PRESSURE DEVICE Filed Aug. 14, 1942 2 Sheets-Sheet 2 FI'G. 3.

IN vsn/rag, 1l/4MM H. Pein,

,9v-Tonner the pressure chamber.

Patented Dec. 7, 1943 FLUID PRESSURE DEVICE William Herbert Rea, Baltimore, Md., assignor of one-half to James H. Easton, Baltimore,

Application August 14, 1942, Serial No. 454,860

(Cl. S- 126) 6 Claims.

This invention relates to uid pressure devices of the internal resistance rotary gear type. The term "iiuid pressure device as herein used is meant to include pumps, fluid brakes and the like. As disclosed in the present instance, the device is used as a pump and may be considered in the nature of an improvement on, or as an alternate construction with respect to the device disclosed in Patent No. 2,270,222, issued January 13, 1942, to'William H. Rea and Arthur W. Weeks. In this patent, a pair of rotary pump gears are enclosed in housing means defining a fluid reservoir and a pressure chamber, and the teeth of the gears are provided with radially movable varies which coact the side sealing strips to eifect a seal between the gears and housing when the said gears are rotated to transfer fluid from the reservoir to the pressure chamber. A' system of ducts are formed in the gears and arranged in a manner such that when the ducts have their inlets presented to the pressure chamber,

the vanes controlled by' said ducts will be forced outwardly under fluid pressure in direct proportion to the amount of pressure generated in While the structure disclosed in the above noted patent may be found satisfactory and efficient for most purposes, yet experience has indicated operation of the device can be improved to obtain a more effective sealing action ofthe radially movable sealingvanes- An object of the present invention, therefore' is to provide a iuid4 pressure device or pump of the internal resistance rotary gear type utilizing radially movable sealing vanes and coacting sealing members of a highly effective type.

Another object is to provide a iiuid pressure device or pump of the type specified of relatively simple construction and design which is capable ci generating practically unlimited pressure at a high rate of efliclency.

A further object is to generally improve fluid pressure devices of the type specified.

rihe foregoing and other objects of the invention will become apparent in view of the following description taken in conjunction with the drawings, wherein:

Figure 1 is a substantially central vertical section of a fluid pressure device or pump in accordance with the invention;

Figs. 2 and 3 are, respectively, sectional views taken substantially on the lines 2-2 and 3-3 of Fig. l;

Fig. 4 is a detail perspective View of one of the sealing vanes and coacting abutment carried by thg pump gears.

Referring to the drawings in detail, a pump housing is generally indicated at I0 and as here shown comprises a peripheral wall Illa and side walls IIlb and I 0c which may be connected to one another in any suitable manner to permit assembly of the respective parts. The housing is provided with an intake port Il and an exhaust port I2, said ports being internally threaded to permit connection to suitable conduits, not shown, leading from a source of supply 4of fluid such as oil and extending to av point of delivery of the uid under pressure.

Within the housing I0 are a pair of coacting gears I3 and I4 which 'may be of substantially the same construction and are so shown, the gear I3 being mounted for rotation on a stubshaft I5 and the gear I being secured 0n a shaft IB, the latter shaft constituting a drive shaft, note Fig. 2, and may extend to a sultable source of power or be driven in any suitable manner, not shown, the housing being provided with boss I1 adapted to receive a. packing gland IB and nut I9 to insure against leakage of fluid around the shaft.

Since the gears I3 and I4 and their coacting sealing vanes and pressure ducts are of substantially the same construction, a description oil one will suffice for both. like reference characters being used for like parts.

Each tooth 20 of the gears is provided with a guide slot 2l, and mounted in this slot is a radially movable vane 22, note Fig. 4, and a ccacting abutment 23, the vane and abutment being cut out to form a recess 24 for a purpose to be described. The vane at its outer end is tapered, as indicated at 22', to provide a wedging action in conjunction with the side walls |017 and Inc of the housing Ill and which are also tapered at this point as indicated at 25. note Fig. 2.

A system of chambers and inlet ducts is provided or communicating pressure to the vanes 22 and abutments 23 in a manner such that there will always be a, plurality of these vanes, as for example three, forced outwardly and exerting a sealing pressure against the inner surface of the housing. The system of chambers and ducts is best shown in Figs. l and 2. The side face of each gear is formed with intake ducts 26, 26a and 26h which conduct iiuid under pressure to preswith coacting pressure chambers 29, 29a and 29h in turn communicating with transversely extending chambers 290 which lead into the slots 2I adjacent the recesses 24. The transverse' chambers .21c communicate through drilled holes or ports 30 with the bottom of the abutment 23.

It will be seen that when fluid under pressure is applied to the pressure chambers 21, 21a, 21h and 210, this pressure is exerted on the abutments 23 which in turn act on the vanes: and move the latter radially outwardly'into sealing engagement with the wall of the ,housing I; and in a like manner, when fluid under pressure is applied to the pressure chambers I!!!y 29a, 29h and 29o, this pressure is communicated to the slots 24 and thence directly to the base of the vanes 22, whereupon the Vane is again forced outwardly into sealing relation with the wall of said housing. Each chamber 21, 21a, 2lb accommodates a plurality of vanes, five in the example shown, and this is also true with respect to the chambers 29, 29a, 29h; and these vane pressure chambers overlap in their operation, viz: pressure is communioated to one chamber before the inlet duct to the other chamber passes out of the pressure area 32.

The area indicated at 3i within the housing III at the point where the intake port I I is located may be considered a fluid chamber or reservoir, while the area 32 adjacent the exhaust port I2 may be considered a pressure chamber or area, the fluid being" taken by the teeth of the gears from the reservoir 3| and carried around to the said pressure area 32.

'Ihe gears are preferably provided with wear plates 33 and 33 at opposite sides thereof which may be made of hardened steel or other suitable Wear resistant material; and to insure against leakage of iiuid between the sides of the gears and the adjacent walls of the housing, side sealing strips 34, 34a, and 34', 32a are provided and located in recesses 35. note particularly Fig. 3 formed in the side walls Ib and Ille of the housing I 0, said recesses dening ports 36 which are fed with iiuid under pressure by means of ducts 31 and 31a formed in said side walls and communicating with the pressure area or chamber 32 through intake ports 31 and 31a. rThese side sealing strips SII-34a have a functionV comparable to the piston rings for the pistons of an internal combustion engine, the said strips being forced against the sides of the gears or the wear plates carried by said gears in direct proportion to the pressure built up in the pressure chamber 32. It will be noted that these sealing strips are arranged in the form of an inverted V and eiiectively seal the boundary of the pressure area at the sides of the housing.

The improved pump or pressure device operates as follows:

The gears I and I6 are driven or rotate in reverse directions, and as rotation takes place the teeth lof the gears pick up uid in the chamber or reservoir 3I and carry it around the pressure chamber or area 32. As pressure builds up in this latter area, iiuid is forced into the respective vane pressure chambers 21-210 and 25J-29e through intake ducts or ports 26, 26a, 26h and 28, 28a and 28h as these inlet ducts move into the pressure area. When pressure builds up in the vane pressure chambers 21-210 this pressure is applied on the abutments 23 which in turn thrusts the vanes 22 radially outwardly into sea-ling engagement with the vwall of the housing; and when pressure is built up in the vane pressure chambers 29-29c, this pressure is transmitted to the recesses 24 and causes the vanes 22 to again move outwardly while the abutments remain seated. The inlet ducts to the respective vane pressure chambers are so located that the operation is alternate With respect to each pair of radiallyspaced vane pressure chambers, that is, the thrust is applied to the abutments at one time and to the vane direct at another. In the arrangement of vane pressure chambers and coactlng inlet ports therefor as shown in the present instance, there will be at least three vanes constantly exerting a sealing pressure or thrust against the wall of the housing, thereby insuring an eiective seal at this point. In conjunction with this sealing action, pressure is transmitted to the side sealing strips 34-34a' through ports 31', 31a' and ducts 31, 31a, causing said strips to be forced against the sides of the gears or the gear plates carried by said gears, thereby also effectively sealing against leakage of iluid at these points.

Machining of gears and production of coacting parts is much simplified by the construction herein disclosed, and uninterrupted operation over a long period of use is assured. 'I'he pump may be made small and compact and adapted for a wide variety of uses; it may be made as a sealed unit and installed in a restricted space.

It will be understood that no attempt has been made herein to show the exact relative dimensions of gears and teeth and other mechanical parts of the capacities of the pressure ducts, it being obvious that the drawings are illustrative of the invention and various changes in construction and design of the respective parts may be adopted Without departing from the spirit or scope of the invention as dened by the appended claims.

What is claimed is:

1. In an internal resistance rotary gear type :duid pressure device, a housing defining a pump chamber, a pair of intermeshing pump gears mounted in said chamber and rotatable to build up pressure in an area in said chamber, said gears being formed with a serles of radial guide slots, a series of sealing vanes mounted in said slots for radial movement outwardly into sealing contact with the wall of said chamber, said gears being also formed with a plurality of vane pressure chambers spaced from one another circumferentially in each gear and also radiallyon opposite sides of the gear,' each of said vane pressure chambers communicating with a plurality of said slots to thereby control a plurality of vanes, said gears being further formed With a series of inlet ducts, one duct for each vane pressure chamber, said ducts being located on the gears in a manner such that there will always be at least two of said ducts simultaneously communicating with said pressure area to thereby constantly maintain a plurality of vanes in sealing contact with the wall A of the pump chamber.

2. In an internal resistance rotary gear type fluid pressure device, a housing defining a pump chamber, a pair of intermeshing pump gears rotatably mounted in said chamber, rotation of said gears functioning to build up pressure in an area in the pump chamber, said gears being 'formed with a series of radial guide slots, sealing vanes mounted for radial movement in said slots, said gears being also formed with a plurality of sepas rate vane pressure chambers communicating at f radially spaced points with said guide slots, each of said chambers controlling a segment of a gear embodying two or more vanes, said vane pressure to thereby constantly maintain a assauts chambers overlapping one another around each gear so that each vaneis under the control of at least two chambers, said vane pressure chambers being provided with inlet ducts so located with respect to the peripheries of said gears as toresuit in at least two of said ducts being always within the pressure area of the pump chamber during rotation of the gears to thereby constantly maintain a plurality oi sealing vanes in contact with the wall of the housing.

3. In an internal resistance rotary gear type iluid pressure device, a housing dening a pump chamber, a pair of intermeshing pump gears rotatably mounted in said chamber, rotation of said gears functioning lto build up pressure in an area in the pump chamber, said gears being formed with a series of radial guide slots, sealing vanes mounted for radial movement in said slots, said gears being also formed with a plurality of separate vane pressure chambers communicating at radially spaced points with said guide slots, said vane pressure chambers being provided with inlet ducts so located with respect to the peripheres of said gears as to result in at least two of said ducts being always within the pressure area of the pump chamber during rotation or the gears plurality of sealing vanes in contact with the wall of the housing, and an abutment disposed in each ot said guide slots at the base of the vane, said vane pressure chambers communicating pressure alternately indirectly to each vane through its abutment and directly with the vane, the construction and arrangement being such that the abutment moves with the vane under the influence of indirect pressure and remains seated under the influence of direct pressure.

4. In an internal resistance rotary gear type fluid pressure device of the type utilizing a pair of interrneshing pump gears mounted for rotation in a pump chamber and provided with radially movable sealing varies, said gears being formed with radial guide slots for said vanes, an abutment mounted in each slot at the base of the vane therein and movable with the latter, there being a recess formed between the abutment and vane, said gears being also formed with vane pressure chambers respectively communicating with each guide slot at the base of the abutment and at said recess, said gears being further formed with inlet ducts for said vane pressure chambers arranged to communicate duid pressure from the sure device of the of said vane pressure pump chamber alternately to said abutment and directly with the vane.

5. In an internal rotary gear type fluid prestype utilizing a pair of intermeshing pump gears mounted for rotation in a pump chamber and provided with radially movable sealing varies. said gears being formed with radial guide slots for said vanes vand a series of vane pressurechambers communicating at radially spaced points with said guide slots, an abutment mounted in each guide slot and movable with its coacting vane, there being a recess formed between the abutment and vane, one of said vane pressure chambers communicating with an abutment at the base of the latter and another of said chambers communicating with the slot in which the abutment is mounted between the abutment and its coacting vane, said vane pressure chambers having individual inlet ductsarranged to communicate pressure from the pump chamber to said vane pressure chambers during rotation of the gears.

6. In an internal resistance rotary gear type fluid pressure device, a housing defining a pump chamber, said housing having a uid intake port and an exhaust port, a pair of mtermeshing pump gears rotatably mounted in said chamber,

rotation of said gears transferring fluid received through said intake port to an area adjacent the exhaust port and building up pressure in said latter area, said gears having a series of guide slots, sealing vanes mounted for radial movement in said guide slots, said gears each having a series of separate circumferentially-spaced vane pressure chambers located at different radial points on opposite sides of the geareach pressure chamber controlling a segmental portion of the gear embodying a plurality of vanes and said vane pressure chambers being arranged to overlap one another around each gear so that each slot is under the influence of two chambers, an abutment mounted in each slot at the base of the vane therein, there being a recess or space formed between each abutment and its coacting vane, one chambers communicating with a guide slot at therein and a vane pressure chamber communieating with said last mentioned slot at said recess,

and separate intake ports for said vane pressure chambers.

WILLIAM HERBERT REA.

the base of the abutment- 

